Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
  • G03G5/0601—Acyclic or carbocyclic compounds
  • G03G5/0609—Acyclic or carbocyclic compounds containing oxygen

Definitions

• Bianthrone compounds including those having halogen, lower alkyl and hydrogen substituents in the ring structure, are used to sensitize organic photoconductive systems so that they will respond to electromagnetic radiation in the visible portion of the spectrum. Typical of the sensitizers that can be used are 2,2-dibromobianthrone and bianthrone.
• This invention relates generally to sensitizers for organic photoconductive members, and in particular, relates to the addition of bianthrone-type compounds for the purpose of increasing the sensitivity range to electromagnetic radiation in the visible portion of the spectrum.
• a recording member is prepared by applying a photoconductive layer to a conductive support.
• organic compounds are known to have utility in electrophotographic systems such as aromatic compounds which may include naphthalene, biphenyl, fluorene, anthracene, phenanthrene, acenaphthene, chrysene, diphenylamine, and carbazole; polymeric organic photoconductors which include polystyrenes, polyvinylxylenes, polyvinylcarbazoles, poly-wvinylnaphthalene, polyindene and polycarbonates.
• R R R R R and R represent lower alkyl, halogen, and hydrogen substituents, and R R R R R and R can be the same or different, extend the photo response of organic photoconductive systems into the visible portion of the spectrum.
• the sensitizer is added to the solution containing the polymeric photoconductive material or to the dispersion in which the crystals of photoconductive material are dispersed in a resin binder.
• the organic photoconductor solution or dispersion there is added in the range of 0.2 percent to 100 percent by weight of sensitizer based on the weight of the or ganic photoconductive material in order to extend the photoresponse of the photoconductive layer to the visible range of the spectrum.
• the organic photoconductor is a polymeric material which itself forms a film it is necessary to first put the sensitizers of this invention into solution. Understandably, the amount of the sensitizer that can be included in with a polymeric-type photoconductive system will be governed by the amount of material that can be put into solution.
• the bianthrone derivatives may be added directly up to percent based on the weight of the organic photoconductive material.
• Chlorobenzene has been found to be a suitable solvent for the bianthrones and its derivatives permitting concentration of sensitizer up to 10 percent by weight of the organic photoconductor.
• the preferred sensitizers are the halogen and hydrogen substituted bianthrone compounds. However, excellent sensitizing effects are obtained using the alkyl and fluoro derivatives.
• the combination of ingredients is thoroughly mixed so that in the case of the polymeric photoconductive systems complete and uniform solution occurs.
• the materials are ball milled for a period of approximately 24 hours to obtain uniform blending of all ingredients.
• the mixture is then applied to a suitable substrate having the proper conductivity by such known techniques as a meniscus coater or trailing-blade coater, applying a thin film of the coating solution or dispersion to the surface.
• the solvent is then evaporated by forced air drying by passing the coating web through a heated oven.
• EXAMPLE V Polyvinylcarbazole 5 z. Chlorobenzene 65 g. 7.7'Dibromo-2,2',3.3- tetramethylbiunthrone EXAMPLE v1
• the coating formulation of this example is a dispersion of the photoconductive material in a resin binder.
• the crystals of 2,3 benzophenylene oxide are dispersed in a resin dissoved in a solvent and the sensitizer is then dispersed in the resin binder.
• the ingredients are balled milled for about 24 hours until the dispersion is uniform and applied to a suitable base support.
• EXAMPLE VIII The coating formulation of this example is a dispersion type.
• EXAMPLE VIII The coating formulation ofthis example is a dispersion type.
• Triphenylene g. Slyrene-butadiene resin 10 g Toluene 50 g. Bianthrone 2 g.
• the photoelectrostatic members in each of the examples may be imaged by charging to a saturation voltage of 800 volts and then exposed to electromagnetic radiation in the visible range, such as is emitted by a Sylvania filament lamp contained in a quartz envelope rated at an intensity of 36 foot candles, which discharges the member to a level of 300 volts in a period ranging from 0.2-8 seconds.
• electromagnetic radiation in the visible range such as is emitted by a Sylvania filament lamp contained in a quartz envelope rated at an intensity of 36 foot candles, which discharges the member to a level of 300 volts in a period ranging from 0.2-8 seconds.
• the time required to realize a voltage drop from a saturation level of 800 volts to the same level of 300 volts was in excess of seconds.
• organic photoconductive material may be selected from the list of organic photoconductors disclosed herein which is only a partial list using either the monomeric form contained in an inert resin hinder or a polymer capable of forming a continuous film when applied to a substrate and the effect of the sensitizers may be realized without limitation to the type of organic photoconductor employed.
• a photoelectrostatic recording element comprising a conductive base coated with an aromatic organic photoconductor and a sensitizer having the formula where R,, R R R,, R, and R represent lower alkyl, halogen, and hydrogen substituents and R R R R,, R, and R; can be the same or different, said sensitizer being present in the range of 0.2 percent to 100 percent by weight based on the weight of organic photoconductor.
• R R R R R and R represent lower alkyl, halogen and hydrogen substituents and R, R R R R and R can be the same or different, said sensitizer being present in the range of 0.2 percent to 100 percent by weight based on the weight of organic photoconductor.

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• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Photoreceptors In Electrophotography (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=25231339

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (2)

• 1969
  • 1969-04-30 US US820634A patent/US3615411A/en not_active Expired - Lifetime
• 1970
  • 1970-04-06 GB GB06138/70A patent/GB1281119A/en not_active Expired
  • 1970-04-22 NL NL7005837A patent/NL7005837A/xx not_active Application Discontinuation
  • 1970-04-24 JP JP45034841A patent/JPS4813064B1/ja active Pending
  • 1970-04-29 DE DE2021132A patent/DE2021132C3/de not_active Expired
  • 1970-04-30 BE BE749839D patent/BE749839A/fr unknown
  • 1970-04-30 FR FR7015945A patent/FR2040495A1/fr not_active Withdrawn

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